Oncostatin M-induced growth inhibition and morphological changes of MDA-MB231 breast cancer cells are abolished by blocking the MEK/ERK signaling pathway

Breast Cancer Res Treat. 2001 Mar;66(2):111-21. doi: 10.1023/a:1010614724664.


Cytokine oncostatin M (OM) has profound effects on proliferation and differentiation of breast cancer cells. OM treated cells show reduced growth rate and differentiated phenotypes. The mechanisms underlying the OM growth-inhibitory activity in breast cancer cells have not been fully elucidated. In this study, we investigated the OM-elicited signaling pathways in breast cancer cell lines MDA-MB231 and MCF-7. We show that OM rapidly activates the extracellular signal-regulated kinase (ERK) and the signal transducer and activator of transcription (STAT) 1 and 3 in both cell lines. Intriguingly, OM-induced growth inhibition and morphological changes in MDA-MB231 cells are completely abolished by inhibitors to ERK upstream kinase MEK (nitrogen/extracellular-regulated protein kinase kinase), but the MEK inhibitors have little effects on OM growth-inhibitory activity in MCF-7 cells. In addition, expressions of the cyclin kinase inhibitors p21 and p27 are strongly induced by OM in MCF-7 cells, but their expression is only slightly increased by OM in MDA-MB231 cells. These data together demonstrate that the growth-inhibitory activity of OM can be mediated by different signaling pathways in a cell line-specific manner. While the MEK/ERK pathway is the predominant signaling pathway that leads to the growth inhibition of MDA-MB231 cells, activation of additional signaling pathways are necessary for OM to exert its growth-inhibitory activity in MCF-7 cells.

Publication types

  • Research Support, U.S. Gov't, Non-P.H.S.
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Blotting, Western
  • Breast Neoplasms / pathology*
  • Cell Division / drug effects*
  • Female
  • Humans
  • MAP Kinase Kinase Kinase 1*
  • MAP Kinase Signaling System
  • Mitogen-Activated Protein Kinases / metabolism*
  • Oncostatin M
  • Peptides / pharmacology*
  • Protein-Serine-Threonine Kinases / metabolism*
  • Tumor Cells, Cultured / drug effects


  • OSM protein, human
  • Peptides
  • Oncostatin M
  • Protein-Serine-Threonine Kinases
  • Mitogen-Activated Protein Kinases
  • MAP Kinase Kinase Kinase 1
  • MAP3K1 protein, human